var http = require('http')
var cheerio = require('cheerio')
var url = 'http://www.imooc.com/learn/348'

function filterChapters (html) {
	var $ = cheerio.load(html)
	chapters = $('.chapter')
	/*[{
		chapterTitle:'',
		video : [
			title : ''
			id : ''
		]
	}]*/

	var courseData = []

	chapters.each(function(item){
		var chapter = $(this)
		var chapterTitle = chapter.find('strong').text()
		var video = chapter.find('.video').children('li')
		var chapterData = {
			chapterTitle : chapterTitle,
			videos:[],
		}

		video.each(function(item){
			var video = $(this).find('.J-media-item')//J-media-item studyvideo
			var videoTitle = video.text()
			var id = video.attr('href').split('video/')[1]

			chapterData.videos.push({
				title : videoTitle,
				id : id,
			})
		})	

		courseData.push(chapterData)
	})

	return courseData
}

function printCourseInfo (courseData) {
	
	courseData.forEach(function(item){
		var chapterTitle = item.chapterTitle
		console.log(chapterTitle+'\n')

		item.videos.forEach(function(video){
			console.log('	【'+video.id+'】' + video.title + '\n')
		})
	})

}

http.get(url,function(res){
	var html = ''

	res.on('data',function(data){
		html += data
	})

	res.on('end',function(){
		//console.log(html)
		var courseData = filterChapters(html) 
		printCourseInfo(courseData)
	})
}).on('error',function(){
	console.log('获取课程信息出错！')
})